Disclaimer: this is purposefully obtuse.
Other effects in the game which explicitly state they kill you:
Shadows, succubi, massive damage, death saving throws, beholder death ray (notably not even their disintegration ray kills you), power word kill, vampires, mind flayers, night hags, drow inquisitors.
Clearly, if they intended for disintegration to kill you, they'd have said so. Since specific overrides general, and there is no general rule that disintegrated creatures are dead, I rest my case. QED.
The rules also don't state that being incapacitated impairs movement in any way, dropping to 0hp is stated to incapacitate you. So you can just move away at 0hp.
Obviously we have DMs who aren't robots and will play to the spirit of the game, not the word of the rules.
Do they need to define dictionary words? You are incapacitated, you don't have capacity to do that.
The lack of qualification indicates you are completely incapacitated and have no capacity to do or say anything.
The rules state that you either die or fall unconscious when you have 0 hit points. The definition of "unconscious" in Appendix A specifies that you are incapacitated AND can't move or speak AND are unaware of your surroundings.
EDIT: Maybe I shouldn't assume you're talking about 5e. I have no idea about 5.5e or any other edition
No, dropping to 0 hit points makes you unconscious, not incapacitated. That's an important distinction. It's the unconscious part that impairs your movement.